EuroDASS Praetorian

from Wikipedia, the free encyclopedia
Eurofighter maneuvering at great heights during exercise Taurus Mountain

The EuroDASS Praetorian is the self-protection system of the Eurofighter Typhoon , which is manufactured by the EuroDASS consortium, consisting of Airbus Group , BAE Systems , Elettronica and Indra Sistemas . The development phase was marked by changeable political decisions, which led to delays. Although the development of the self-protection system, formerly known as the Defensive AIDS Subsystem (DASS), at over £ 1.5bn (€ 1.8bn) is the second most expensive component of the aircraft after the Eurojet (£ 1.66bn), is least known about it. When the first concept was created in 1987, new territory was broken in some areas: EloUM / EloGM antennas with active electronic beam swiveling, calculation of a fire control solution through emitter orientation, millimeter-wave radar for rocket location, tow jammers for an agile combat aircraft and the calculation of maneuvering instructions for the pilot for emitter orientation and missile avoidance. The Future Offensive Air System (FOAS) study is likely to have incorporated further ideas, but there are no explicit comments.

history

The Defense Aids Subsystem (DASS) has always been seen as an integral part of the airframe. In 1987, the concepts of Marconi, Elettronica and Ensa envisaged combining systems for electronic countermeasures (ECM), electronic support measures (ESM), rocket warning devices with active radar (MAW) and laser warning devices (LWR), as well as chaff and flare throwers into one system. A novelty for a maneuverable combat aircraft was the conception of three tow jammers, each of which was to be pulled behind the aircraft on a 100 m long rope. If necessary, the rope should be able to be cut. In order to exclude the risk of collision, simulations were carried out which came to the conclusion that only the loss of power in a vertical climb with subsequent sagging could lead to the rope becoming entangled with the aircraft. The initial spatial division of the systems is a bit confused: ESM, ECM, MAW and laser warner should be housed in the pods, on the other hand there is talk of further phased array antennas in the wing roots. In the course of the design phase, the pod disappeared in the vertical stabilizer; this was no longer considered necessary. The integration of all systems into a system of systems should make it possible to deflect an infrared-guided missile from the aircraft with just one flare.

In 1988 Ferranti toyed with the idea of ​​developing an electro-optical missile warning system for the EFA, and AEG joined the Marconi-led EuroDASS consortium in September. In 1990, Eurofighter Jagdflugzeug GmbH discussed with the partner countries whether the DASS should also be put out to tender outside the four-partner contract. The conversation was with Loral and Dassault , instead of the EuroDASS consortium. BAE Systems rejected these plans because the DASS also requires data from the entire avionics and flight control system (FCS) for defense maneuvers. The defense system should be tendered in eight packages, with category A (ESM, ECM, laser, missile warning), category B (dispenser, DASS computer) and category C (decoys). The first package was finally put out to tender in August 1990. At the same time, discussions began with the US company Texas Instruments, as the active radar jammer GENeric eXpendable (GEN-X) was to be dropped from the dispensers.

However, the procurement project collapsed in 1991 because Germany wanted to withdraw from the EuroDASS project due to the high costs. From this point on there were massive delays: DA1 was almost completed in Ottobrunn and construction of DA2 started in Warton. PIRATE was already three years behind schedule and an agreement on the defense system was not in sight. Germany only wanted radar and missile detectors and so Telefunken Systemtechnik, as a German company in the EuroDASS consortium, was only assigned observer status. In November 1991, Germany put out its own contract to equip the German Eurofighters with radar and missile detectors. In February 1992, shortly before the £ 1.5 billion (€ 1.87 billion) DASS contract was signed, Spain began to have doubts about the financial viability of the EFA. Meanwhile, Germany had received offers for its tender on January 30, but was again considering working with EuroDASS in the middle of the year. Ultimately, the treaty was signed without Germany and with Spanish reservations in February 1992. Since Great Britain and Italy were the only countries in the EuroDASS consortium, the work shares were split between 60% and 40%. A total of five offers were necessary before the contract was awarded. It was determined that the jammers in the pods would work with active phased array antennas in order to be able to interfere with several radars at the same time. Multiple tow jammers should be housed in the starboard pod. The ESM system should use spiral antennas and send data to the jammers, the weapons master computer, the head-up display and the head-down displays. The Plessey Avionics missile warning system should be located in the front wing roots and at the end of the vertical stabilizer and work with active radar.

In 1993 Spain planned to rejoin the EuroDASS consortium. At the same time, the number of targets that should be disrupted at the same time was reduced. Spain returned to the consortium in 1995. In 1996 Germany did plan to integrate a tow jammer into the Eurofighter, which should also be used by the Transall . Now there was also an opportunity here to return to the consortium. In May 1996 the Federal Republic of Germany decided to buy the DASS, although no German company was involved in its development and production. Going it alone nationally had proven too expensive. Top managers from DASA and GEC-Marconi met in July because DASA wanted a production share. This failed, however, so that tens of millions of marks were ultimately lost for the development of radar detectors, electro-optical missile detectors and a tow jammer. DASA had no choice but to attract customers for these systems in other ways. The tow jammer was tested for the first time with DA2 in August 1996. In April 1997 the possibility of dropping the active radar jammer GEN-X via the dispenser was dropped. At the end of 1997 DASA was still trying to win at least the contract for the tow jammers for the German Eurofighters. At the beginning of 1998, the first supersonic flight of DA2 was completed with the tow jammer and six missiles, while DASA continued to try to get a foot in the program and the German Air Force tested the GEC-Marconi tow jammer on the Panavia Tornado . Until the beginning of 1998, the GEC-Marconi drag jammer, which was now called "Ariel", was tested up to Mach 2, while DASA continued to use its drag jammer, which was only tested up to Mach 1.4 and was not integrated into the Defensive Aids Computer (DAC) , Lobbying operation. The entire DASS was approved with the IPAs.

As part of the Future Offensive Air System (FOAS) study, work on AMSAR began in 1993 . The FOAS should use this technology to carry small radar systems on the wing roots, fore fuselage and tail to increase the field of view. This would also increase flexibility in combat, as opponents could be located and shot at with missiles without pointing the aircraft's nose at them. In 2000, after the Eurofighter was determined as the main platform for FOAS, the ominous announcement followed that the Eurofighters of Tranche 3, which were to be delivered from 2010, should have 360 ​​° sensor coverage. In 2001 the production contract for Tranche 1 machines was finally signed, at the same time EADS / DASA joined the consortium.

On June 13, 2003, the first series-produced Eurofighter was finally presented to the public. The Bundeswehr accepted the machine on August 4th of the same year. The complete Praetorian self-protection system is only available from tranche 1 block 2B. Various indications suggest that the missile warning systems from section 2, block 10, along with the low-band antennas, were upgraded. From mid-2014 there will also be an active, detachable radar jammer from the European Selex ES that can be scaffolded upon customer request.

overview

F-16 with ALQ-131 on the central fuselage

Before the Vietnam and Six Day War, electronic combat played no role for tactical combat aircraft: there were no radar detectors, missiles had to be recognized with the naked eye, decoys and the disruption of radar systems was not considered necessary. Only the problems with anti-aircraft missiles in these wars made chaff launchers and distance jammers such as the EB-66 appear necessary. Tactical jammers and AGM-45 Shrike for combat aircraft were only intended for the Wild Weasel concept. The aircraft of the next generation (F-14/15/16/18, MiG-29, Su-27, Tornado), unlike bombers, only have modest internal equipment for electronic combat; external containers like the AN / ALQ-131 carried. Only with the latest generation of combat aircraft (Eurofighter, Rafale, MiG-MFI, F-35) are all systems integrated in the fuselage to reduce air resistance. In addition to the use of Active Electronically Scanned Arrays as jammers, tow jammers have also been developed to actively counteract radar-guided missiles such as AIM-120 and R-77 .

At the same time, the individual subsystems also became more and more powerful: The SPO-15LM radar warning receiver of a MiG-29 and Su-27 consists of B. only from an analog display that shows the signal strength, the angle of the greatest radar threat and the type of greatest threat (AWACS, air surveillance radar, short range SAM, medium range SAM, long range SAM, fighter aircraft radar). The azimuth angle is indicated by eight azimuth sectors in the front half, in the rear area a distinction is only made between rear right and rear left. The elevation display shows whether the emitter that represents the greatest threat is above or below your own machine, or at the same height. The radar detector of an F-16, on the other hand, has a digital display that shows what is happening directly from above, and is ergonomically positioned more favorably. The angle determination is much more precise here and enables the pilot to observe several emitters at the same time. These are identified by the computer so that the type (Su-27, F-15, etc.) can be displayed. However, the measurement is not precise enough to determine the distance; instead, the distance from your own aircraft is selected on the display according to the threat situation and the signal strength.

The Rafale can camouflage itself from radar devices through active extinction

In the last few years there has been intensive research into purely passive localization of emitters. The problem here is that the angular displacements are too small over longer distances, and so one is dependent on several platforms, which have to determine an angle to the emitter and merge the result in order to determine an intersection point. Since not all receivers receive the same pulse at the same time, synchronization is hardly possible; BAE Systems therefore developed a method in which the signals are received independently of one another and then compared. The system will also be used in the F-35. The AN / ALR-94 of the F-22 is also precise enough to be used for determining the distance and thus also for fire control. In the case of the Eurofighter, the focus is less on the ability to track emitters for passive fire control; instead, emphasis is placed on the possibility of conducting aerial combat with the IRST in a purely passive manner, even over long distances .

Missile warning devices based on UV, IR or radar emerged in the 1980s to warn of infrared guided missiles such as the AIM-9 Sidewinder. Since UV systems can only locate the exhaust jet of a (rocket) engine, they are increasingly unpopular in modern combat aircraft. Radar-based systems are more independent of the weather, the distance can be determined more easily and the propulsion phase (ignited / burned down) of the missile does not matter. However, the relative angular inaccuracy and the locatability of the radar are disadvantageous. The range of infrared-based systems depends on the weather and the phase of the drive, and the determination of the distance depends on an angle change for sequential triangulation. However, the system is passive and cannot be located by the enemy. Which system is used is a matter of taste. B. All Israeli helicopters radar missile detectors. Older systems such as the AN / ALQ-156A work in an omnidirectional manner in order to locate threats in the vicinity in sectors. Modern systems, such as the armored vehicles Merkava or K2 Black Panther use phased- F / G-band (3-6 GHz) and K a to threats to locate band radar (35 GHz), precisely.

Due to the development of IRST with laser rangefinders, the Eurofighters are also being equipped with laser alarms, after torches had already proven their usefulness in the Falklands War . Saab's BOL dispensers, with 2 × 160 packages, ensure large-scale contamination of the airspace with radar reflectors or infrared sources, while the Cobham dispensers with 2 × 16 programmable decoys focus on quality instead of mass. The active radar baits intended for these dispensers, however, fell victim to the budget, currently only the “intelligent” ejection of torches is possible.

technology

Defensive AIDS computer

Position of the subsystems:
1. Laser warner
2. Cobham dispenser
3. BOL dispenser
4. Missile warner
5. ESM / ECM pods
6. Tow jammers

The self-protection system consists of antennas for electronic countermeasures (ECM) and electronic support measures (ESM), as well as missile alarms (MAW), laser alarms and decoys. The system is divided into up to 22 LRUs. The individual components are controlled by the Defensive Aids Computer (DAC) via MIL-STD-1553 data buses, while the computer itself is connected to the avionics via fiber optic cables in accordance with STANAG 3910 . The entire system is controlled by five Radstone PowerPC-4 processors, which increases the computing power tenfold compared to the original five Motorola 68020 . Normally it works fully automatically, which relieves the pilot considerably in combat. But there are also manual override options.

The ESM / ECM wing tip containers of the Eurofighter Typhoon contain highly sensitive overlay broadband receivers which, in addition to their function as radar warning receivers, are also able to detect other electronic emissions such as B. radio and data transmission or interference attempts. The system carries out a constant passive search in the frequency range from 100 MHz to 18 GHz, with later versions probably up to 40 GHz. The signals received by the sensors are analyzed , categorized , identified , prioritized and localized . This information is forwarded to the Defensive Aids Computer (DAC) together with the data from the laser warning device, where the DAC uses a library containing 65,536 signal examples (as of 2012) to identify the type of transmitter and determine which operating mode it is in, which weapon system is involved and prioritizes according to the level of danger. To do this, the DAC can access the kinematics of its own aircraft, the positions of the antennas on the aircraft, the position of the buoyancy aids and a database with radar and infrared cross-sections and the optical signature of the Eurofighters from every angle. By identifying the opponent's platform on the basis of emitter identity or suspected target type, based on systems that are in the opponent's inventory, the possible weapon load of the opponent is determined, as well as their effective range and tactical use. These libraries are freely programmable for the Eurofighter operators and can be adapted to the current threat situation at any time.

When flying with high g-loads, information is sent from the Flight Control System (FCS) to the ESM in order to take into account the deflection of the wings when determining the position of the targets. The ESM estimates the distance to the target based on the signal amplitude. The bearing accuracy is less than 1 ° higher than with CAPTOR radar. Due to its high angular precision, the system can also be used for geolocation of emitters and fire control. Determining the position of air targets is challenging because they move at an unknown distance, with an unknown course and an unknown speed. To solve the problem, two Kalman filters are used for a recursive Interacting Multiple Model (IMM), which uses the antenna positions, interferometry measurements for angle determination, the Pulse Descriptor Word (PDW), mission data , real-time boundary conditions and track data from other sensors to Output distance, speed and heading of the target. If the change in angle is too small, e.g. B. because the transmitter is located a long way away or directly in front of the aircraft, there are two options:

The wingmen send angle measurements and the PDW via the data link. This data is correlated over time via angle, signal-to-noise ratio, SEI (Specific Emitter ID of the threat / target radar) . Your own machine and that of the wingmen can determine the target positions, as the distance between your own aircraft is known ( triangulation ). If this option is not available, the second option takes effect: The DAC calculates whether there is enough information about the emitter to give the pilot maneuvering instructions on the HUD. If this is the case, two standard maneuvers are available: With the 2-turn, two 90 ° turns are flown with a straight line in between, so that the flight direction after the maneuver is identical to the previous one. The second maneuver is sinusoidal , in principle the emitter is approached in a zigzag. The displays in the HUD are like when avoiding missiles; an arrow indicates the direction and g-force , the course and the duration of the maneuver are also displayed.

In the event that there is no antenna in the vertical stabilizer (see below), BAE Systems has a second patent that can only calculate target positions in three dimensions using azimuth measurements, maneuver overlays and data links. The data processing is more complex with 12 Kalman filters, since angle measurements, the PDW and other things also have to be correlated internally in a database. The interacting multiple model also differentiates here whether the aerial target is maneuvering or maintaining its course. Otherwise the data processing is identical to that described above. The maximum range of the method is given as 120 nm (216 km).

In principle, this is only possible in the front hemisphere, since the right pod at the rear contains the tow jammers. In the rear hemisphere, only a rough indication of the angle (6–18 GHz or 32–38 GHz) or the sector (0.1–6 GHz) such as bottom left, top right etc. is possible.

Electronic warfare

ESM-ECM

When the requirements for an ECM system for the European Fighter Aircraft (EFA) were published, these could only be met by antennas with active electronic beam swiveling. Since the effective radiated power of the AESA antennas at that time was still low, the technical progress during development was relied on. Elettronica and GEC Marconi were finally awarded the contract for the first ECM system, which consists entirely of semiconductor components.

The individual transmitting and receiving modules consist of Vivaldi antennas , which can also passively localize emitters. The antennas are in the front of the wing tip canisters and another is in the back of the left pod. The T / R modules of the AESAs are manufactured as MMICs on a GaAs basis and work in the frequency range of 6-18 GHz. The power per module is 27 dBm (0.5 watt) before the energy is amplified by 20 dB (100 times) in an amplifier and emitted after a changeover switch , so that 50 watts of radiation are achieved per Vivaldi antenna plate. Each antenna plate is constructed as a hybrid circuit and contains a row of Vivaldi antennas, similar to spread fingers, at its end. These plates are stacked on top of each other and built into the pod as AESA. The antennas can work independently or together. For example, a front AESA antenna can occupy a target with noise jamming , while the other takes care of other targets. If the interfering energy of both containers is focused on a target in phase , the effective radiated power at the target increases by 6 dB (twice the field strength). The spatial separation of the pods, the choice of actively phase-controlled antennas and multi-bit DRFM also made cross-eye jamming possible.

Close up of the right wing tip canister

In addition to the actively phased Vivaldi antennas, the front of each pod also contains two outward-facing spiral antennas . At the rear end of the left pod there are four antennas to ensure full coverage of the rear hemisphere, thus ensuring 360 ° coverage. While the Vivaldi AESAs are designed as compact devices with an antenna, transceiver and power supply, lower frequencies are covered by the spiral antennas, whose subsystems are distributed over the pod and the aircraft. In the course of phase 1 enhancement (P1E), these will be replaced by new antennas with polarization diversity in order to differentiate between horizontal, vertical, left and right-handed rotation. The input signal is routed to a preselector , which will probably block everything above 6 GHz, as this frequency range is already covered by the AESAs. Finally, a downconverter follows to mix the signal. The LRUs for preselector , downconverter and the monopulse unit are located between the AESA devices in the middle of the pod. This means that the self-protection system can cover a frequency range down to 100 MHz. On the pods there are small bumps in the front and rear, which represent ECM antennas under a radome . The electronics required for this are integrated in the other LRUs, as the Techniques Generator not only masters passive tracking of emitters, but also multi-bit DRFM. Cross-eye jamming and precise control of amplitude, phase and polarization can be retrofitted. The ECM antennas in the bumps would therefore have to transmit somewhere in the frequency range between 0.1 and 6 GHz. Due to the small size and relatively large wavelength, the antenna gain and thus also the effective radiation power is low, so that airspace search radars can realistically only be covered with impulse response interference . The possibility of controlling amplitude, phase and polarization would also make it possible to camouflage the aircraft against slow or limited-frequency radars through active extinction, as is already used with the Rafale . From Phase 1 Enhancement (P1E), new antennas with polarization diversity have been installed, the frequency range has been expanded, the radiation output has been increased and improved DRFM and EloGM techniques are possible. In the case of machines in Tranche 3, the radiation output was further increased at low frequencies.

As already mentioned above, the pod in the vertical stabilizer could be omitted in the course of development . In principle, an antenna would be required here to determine the elevation angle of emitters. At the former position of the pod, in official sectional drawings of the Eurofighter, a shark fin antenna can be seen on a base integrated in the tail unit below the radome for the UHF / IFF antenna, which is located in the tip of the vertical tail unit. Apparently there is no radome at the position shown and therefore no antenna. It is conceivable that the antenna was integrated into the leading edge of the tail unit, as on the Raptor , or that it also moved under the radome of the UHF / IFF antenna in the tip of the vertical tail unit. However, this is not absolutely necessary for the 3D position determination of emitters, see above.

Tow jammers

Right pod with locking caps for the Ariel Mk-II tow-jammers

In the rear right wing tip container there are two Ariel Mk II towing jammers from SELEX Galileo, one of which can be pulled on a 100 m long Kevlar cable behind the aircraft. A fiber optic cable is incorporated for data transmission, as well as a separate power line for the energy supply. The towing jammer works in the frequency range from 6 to 20 GHz, covers almost the entire sphere and can be caught again after use. It is approved for speeds up to Mach 2 and load multiples of + 9 / -3g. Ariel is controlled by the Techniques Generator to neutralize missiles with home-on-jam technology or to work as a radar bait, which offers radar-guided weapons a larger and more attractive target than the carrier aircraft. Together with the ECM antennas in the wing tip containers, the chaff clouds emitted by the decoy launcher are illuminated to make them appear even more worthwhile as a decoy . In the course of phase 1 enhancement (P1E), the interfering frequency range is reduced to up to 4 GHz (G-band) and the effective radiated power is increased.

Missile warning

AMIDS

About the missile Warner (Missile Approach Warner, MAW) of the Euro Fighter Typhoon least is known. The system is said to be the Advanced Missile Detection System (AMIDS) from Elettronica and SELEX Galileo. Pulse Doppler radar is used to locate threats. There are a total of three warning devices, one in each of the two wing roots and one in the stern. It registers every rocket fired at the aircraft and shows the pilot on the DASS display, as well as their position. There is also a distinction between infrared and radar control. Elettronica supplies the transmitters for the missile warning systems.

GEC-Plessey Avionics received the order in 1991 to develop the rocket warning system for the EFA. There was also talk of a test stand for radar frequencies up to 40 GHz, with the option of increasing this to 95 GHz later. In a scientific publication from 1994 by Elettronica, radar and EW systems based on MMIC are presented; all the systems listed and depicted there are recognizable as part of the DASS-AESA antennas. An MMIC downconverter for the frequency range from 32–38 GHz is also presented in the paper. In 1997 it was announced that GEC-Marconi had started the production of phased array antennas in the frequency range of 35-40 GHz for "military radar and communication systems". 2005 BAE Systems was in a technology presentation a K a band pHEMT MMIC in the frequency range of 32-38 GHz, with the reference to the viewfinder and radar applications.

Since GEC-Plessey Avionics, GEC-Marconi, BAE Systems and SELEX Galileo are different names for the same company due to the merger and no official use of a Këa band AESA radar of the company is known, it can be concluded with high probability that this is the case for the Eurofighter was developed and produced. Consequently, the missile Warner active phased-K are a band radar used in the frequency range of 32-38 GHz to objects within a sphere around the Typhoon, except directly above and below, locate and track. Sources also confirm that millimeter wave radar is used. In sectional images of the Eurofighter it can be seen that the systems in the front wing roots are in two parts. Since Elettronica provides the transmitter and the Paper Down Converter for K a presented band, it is likely that the front antennas use separate transmitter and receiver modules to the FMCW radar work. The reason for this is the danger that hostile anti-radar missiles will trigger the transmitters, which is why these [[Operating mode (Radar) #Low Probability of Intercept (LPI) | Low Probability of Intercept (LPI)]] properties. As early as 1987 in the first conception it was declared that the missile warning system should send with a minimal signal-to-noise ratio . Other skills can be inferred :

DASS advertisement with EloGM information:
Green arrow: Eurofighter interferes with target
Red arrow: Target interferes with Eurofighter
  • Since combat aircraft have a significantly larger reflective surface than guided weapons, they can be located and tracked from a much greater distance. Reason: According to BAE Systems, the Helmet Mounted Symbology System (HMSS) shows the position of enemy machines and guided missiles on the helmet display, whereby the target data can only come from the missile warning system, otherwise the position of enemy missiles would not be possible. Diehl BGT Defense mentions in the IRIS-T product flyer that the weapon can also be instructed on targets with the help of the missile warning system. The picture on the right is from the Eurofighter presentation for Norway. In the DASS display shown, an “ MSL ” contact can be seen in the immediate vicinity, as well as destinations labeled “FLN” and “FLANK” up to 50 nm (90 km) away.
  • The system has Non Cooperative Target Identification (NCTI) properties. Reason: The MAW locates the targets but does not identify them. The Italian trade journal PANORAMA DIFESA reported in mid-2013 that the DASS could identify threats from Block 10 through a database comparison and, if necessary, trigger flares and chaff. The signatures of the targets would have to be uploaded before the start. Since the ESM is already suitable for target identification and the phrase “the signatures of the targets must be uploaded before take-off” also applies to the EuroRADAR CAPTOR , the missile warning system is probably meant. See also “FLN” and “FLANK” above.
  • The system can also be used to query friends and foes. Justification: The STANAG 4579, already available for 2001 NATO IFF system , which in the K a band queries from both answers also performs. The system is also known as the NATO BTID (Battlefield Target Identification Device). Responders should be placed on all platforms, while interrogators are only intended for offensive and reconnaissance platforms. This should enable cross-coalition blue force tracking and reduce self- fire. The Eurofighters could identify each other, which would be particularly advantageous in close combat , as it is faster than NCTI.
  • The missile warning system can also locate moving ground targets. Reason: In order to be able to locate approaching missiles against the background, the Doppler shift must be evaluated ( moving target indication ). In order to be able to locate moving ground targets, only a very small frequency shift needs to be measured. Since STANAG 4579 is also intended for ground vehicles and the Doppler shift is measured anyway, there is no special effort. From block 10 onwards, the HMSS should also represent ground targets. With this message it is also conceivable that these targets are located by PIRATE or CAPTOR or are fixed targets that were programmed in before the start.
  • The K a band AESAS can also EloUM and EloGM be used. Reason: Active Electronically Scanned Arrays can transmit and receive on different frequencies at the same time and in different directions. In 2005 it was reported in the Journal of Electronic Defense that the frequency band of the ESM system should be increased from up to 18 GHz to up to 40 GHz in aircraft from Block 10. Since there have been no modifications to the DASS since then - the antennas were already there - this capability was probably implemented via a software update .
Rod-shaped "radar root" at the stern

The location range can only be estimated: Since the "radar root" at the rear has about the diameter of a seeker of an air-to-air missile, its location range can be used as a basis. The X-band finders 9B-1348E ( R-77 ) and 9B-1103M ( R-27AE ) from AGAT have a detection range of about 10 km against a radar cross-section of 1 m². Since the directivity and antenna gain are approximately inversely proportional to the square of the wavelength, the same dimensions result in a 12.25-fold antenna gain for the K a band . Since this is included in the radar equation with the second root , the location range will be around 3.5 times higher. However, the target RCS also increases with higher frequency, while the atmospheric attenuation reduces the location range. Ultimately, based on the AGAT family of searchers, the following location ranges for the AMIDS can be estimated:

The numbers behind the slash indicate the location range that is obtained from the radar equation if 25 m² of radar cross-section are equated with 90 km location range, based on the Eurofighter presentation for Norway. The similarity of results supporting the suspicion that it was K a is band radar.

PIMAWS

The development of a passive, infrared-based missile warning system for the Eurofighter began in 1997. The development of the Passive IR Missile Approach Warning System (PIMAWS) was financed by the Federal Ministry of Defense and Bodenseewerk Geräteechnik GmbH (BGT) and was not an official part of the Eurofighter project. In phase 1 the optronics were developed and manufactured, in phase 2 it was integrated into the aircraft, and test flights are to have taken place from October 2001. Phase 3, the development of the algorithms, ended in 2003. The objective was to locate infrared-guided air-to-air and surface-to-air missiles with a short range even after the rocket motor burned out at a distance of at least 10 km, a false alarm rate of a maximum of 1–2 per Hour and a detection probability of over 95%.

In order to solve the conflict between the need for large apertures, which would require too much space, and long exposure times, which would require too many sensors (see AN / AAQ-37 ), the step-and-star principle was implemented: The sensor is rotatably mounted and the field of view is stabilized so that the room can be photographed one after the other. A double dove prism was placed in front of the detector field, a CMT with 256 × 256 pixels which worked with wavelengths of 3-5 µm, to scan elevation and azimuth , so that a field of view of 30 ° × 30 ° could be photographed one after the other. In total, 360 ° × 105 ° could be covered by a conical scan, with an update rate of 6 Hz. The image was passed through a Schmidt-Pechan prism after a lens in order to obtain an untwisted image on the detector field. The beam path was corrected using a mirror to compensate for the blurring of the image. Two of these systems were attached to the outside of the wing tip containers in a black box to ensure 360 ​​° coverage in azimuth. The mass of an LRU at the wing tip was 40 kg.

In the first step, the data stream was fed into a Systolic Array Processor (SAP), which can detect around 30,000 events per second. These are isolated and provided with a feature vector either as point events or as contours . In the higher digital signal processors (DSP), the clutter is removed by a motion filter and the tracks of the targets are calculated. If a target is lost, its current position is calculated using the last known course. Since the point of re-acquisition can be assumed in this way, only two scans are sufficient for re-activation. A comparison is carried out in the area where the fields of view of the sensors overlap in order to avoid double locations. If the object is several pixels in size, it can be automatically identified by means of an image comparison (e.g. paraglider, MiG-29, etc.). Then the threats are prioritized. Over 64 targets can be pursued at the same time. PIMAWS can also be used for the following purposes:

  • Hemispheric missile warning: Each side of the aircraft is searched in the range of ± 105 ° and 360 °. The pilot can select individual images or viewing directions, either absolutely or in relation to the Eurofighter. The representation of runways or certain areas to be monitored is conceivable. The image is automatically put together from several individual images.
  • Ringmode missile warning: In this case, the elevation angle is set by the DASS computer or the pilot, so that a 30 ° × 360 ° strip is scanned around the aircraft. The field of view is limited as a result, but the update rate increases to over 15 Hz. The pilot can also select individual images or viewing directions here.
  • Imaging Pointable Forward Looking Infrared Camera: The sensors can be controlled at will to serve as FLIR. Was only realized as a HUD projection. You can also see backwards through the field of view of the sensors.

By default, the system also warns of a collision, e.g. B. in high-rise buildings. For this purpose, the horizon is determined and objects in the direction of flight are recognized and tracked. The change in size per time step is then used to determine whether a collision could occur and a warning is issued. The PIMAWS is connected to the DAC via the MIL-STD-1553 bus. It was also designed to have Directed Infrared Counter Measures . In this case, a sensor fusion with AMIDS should be implemented for target verification. The detection ranges of PIMAWS were short, a change to two bands was rejected because of the lower photon yield. The achieved detection ranges were:

During the test phase, real MANPADS missiles were fired at the aircraft, but without locking the target in order to miss it in a ballistic path. In test flights, PIMAWS was used to observe rural areas, industrial areas and burning oil drums in order to optimize the algorithms.

Dispenser

BOL

Saab's BOL dispensers are located at the end of the LAU-7 launch rails on the outer wing tips. The models, known internally as BOL-510, are controlled via the MIL-STD-1553 data bus, have BITE and can each hold around 7–9 kg of infrared or radar decoys. The attachment near the wing tips ensures that the decoys are distributed in the wake vortices , and there are also air inlets at the end of each dispenser for vortex formation. 160 packages can be loaded per dispenser, which stand one behind the other like slices of toast and are ejected in good time by an electromechanical drive. The following decoys can be loaded:

  • Chaff of the type RR-184: These 45 gram packages contain radar-reflecting fibers, which are released from the package after ejection.
  • Type MJU-52 / B flares: These 54 gram packets contain a special material that is distributed after ejection and quickly oxidizes on contact with air, releasing infrared radiation. The process is almost invisible to the eye, which is why they are suitable for preventive use.

Cobham

In addition, there is another dispenser under each wing, in the housing for the actuators of the inner elevons. Most sources believe that these are made by Elettronica Aster, but only Cobham plc advertises making them. The name of the system is unknown. This consists of a box with 16 angled 55 mm blind holes each into which decoys can be inserted. As a special feature, the dispenser can program these via circuits, since originally active, detachable radar jammers should also be carried along. There are two or three types of ammunition available:

Graphic of the BriteCloud in flight
  • Cartridge Countermeasure 55 mm Typhoon IR Decoy: Was developed by the Chemring Group especially for the Typhoon and can be recognized by the integrated circuits in the torch. This means that the use can be optimized through improved ejection software. There is a magnesium / Teflon / Viton variant and a variant with selective radiation characteristics. The mass is 725 grams. Formerly known as Typhoon IR Decoy No1 Mk1 .
  • GENeric eXpendable : The GEN-X should also be carried in the dispensers, but this was given up for cost reasons. After programming and ejection, four wings unfold, which stabilize the free fall. The GEN-X actively generates interference signals with the help of a lithium battery and MMICs , which are emitted via a spiral antenna in the nose. The disruptive body works as a repeater jammer.
  • The BriteCloud from Selex ES will be available from mid-2014 . The active, dropable radar jammer with DRFM technology is said to be cheaper and twice as effective as older models that only work with simple impulse response interference (i.e. GEN-X). BriteCloud is 200 to 375 mm long, weighs 0.7 to 0.85 kg and has a shelf life of around five years. The transmitter can be active for at least 10 seconds after ejection. Platforms are Eurofighter Typhoon, Saab Gripen and Panavia Tornado. So far, no Eurofighter user is a customer.

Laser warning

British and Spanish Eurofighters will also be equipped with laser alarms. If the aircraft is targeted with a laser, they trigger an alarm. The Eurofighter has four laser alarms on the fuselage: two on the front fuselage in front of the canards and two on the stern behind the wing. These are also built into the Saudi machines.

table

customer ESM-ECM Tow jammers Missile warning Dispenser Laser warning
GermanyGermany Germany Checkmark green.svg Checkmark green.svg Checkmark green.svg Checkmark green.svg X mark.gif
ItalyItaly Italy Checkmark green.svg Checkmark green.svg Checkmark green.svg Checkmark green.svg X mark.gif
AustriaAustria Austria X mark.gif X mark.gif X mark.gif Checkmark green.svg X mark.gif
OmanOman Oman Checkmark green.svg Checkmark green.svg Checkmark green.svg Checkmark green.svg Checkmark green.svg
Saudi ArabiaSaudi Arabia Saudi Arabia Checkmark green.svg Checkmark green.svg Checkmark green.svg Checkmark green.svg Checkmark green.svg
SpainSpain Spain Checkmark green.svg Checkmark green.svg Checkmark green.svg Checkmark green.svg Checkmark green.svg
United KingdomUnited Kingdom United Kingdom Checkmark green.svg Checkmark green.svg Checkmark green.svg Checkmark green.svg Checkmark green.svg

Web links

annotation

  1. ↑ a b c There are numerous references to the possibility of using the ESM to guide guided missiles to targets. Flight International wrote e.g. B. 1992 that the ESM should also send data to the weapons control computer - why, if not for shooting? On its homepage, Elettronica names “targeting due to adoption of very accurate TDOA measurement” as the ability. Only one Eurofighter advertising magazine from 2009 mentions “target acquisition by radar warning receivers and / or radar” as an option. An offensive marketing of this ability does not take place.
  2. ↑ a b c d The statement by Flight International from 1992 that the ESM also sends information to the HUD arouses associations with the display of the evasive course. In fact, BAE Systems' US 6,822,583 B2 also has a corresponding patent from 2002. The data processing and prioritization are also explained here, as is the data exchange between the aircraft. There is no explicit reference to an application on the Eurofighter. However, some of the points mentioned (maneuver overlays, IRST without laser, emitter alignment by two machines) fit very well with the known facts of the Eurofighter. Since both the DASS and the AN / ALR-94 are manufactured by BAE Systems, there will inevitably be overlaps in data processing. It is conceivable that US 6822583 B2 describes the AN / ALR-94, while WO 2006135416 A2 relates to the DASS.
  3. ↑ In addition to pages 27/44, pages 33/44 also seem interesting, but the output here is only 100 mW instead of 5 W per module and the frequency range 36–42 GHz instead of 32–38 GHz.
  4. ↑ The AH-64 Longbow Phased Radar is manufactured by Lockheed and Grumman. Boeing's PAC-3 K a -band finder is mechanically pivoted. The phased radar of the K2 Black Panther was developed by the Thales Group.
  5. ↑ Probably everything

Individual evidence

  1. ↑ Flightglobal: EFA development contracts signed , December 5, 1988 (PDF; 311 kB)
  2. ^ A b Flightglobal: Consortium proposes EFA defensive aids , July 11, 1987
  3. ↑ Flightglobal: Ferranti bids for bigger EFA stake , August 6, 1988
  4. ↑ Flightglobal: AEG joins EFA EW bid , September 17, 1988
  5. ↑ Flightglobal: EFA may use 'foreign' EW , 21-27. March 1990 (PDF; 1.3 MB)
  6. ↑ Flightglobal: Last EFA system RFP due , 8-14. August 1990 (PDF; 2 MB)
  7. ↑ Flightglobal: Eurodass approaches Texas Instruments , October 24, 1990
  8. ↑ Flightglobal: Eurofighter's final systems snag on cost , June 26, 1991
  9. ↑ Flightglobal: Germany reviews common DASS for EFA , 7-13. August 1991 (PDF; 1.3 MB)
  10. ↑ Flightglobal: Germany issues solo tender for EFA , 6-12. November 1991
  11. ↑ Flightglobal: Spain dithers on Eurofighter DASS choice , 5-11. February 1992
  12. ↑ Flightglobal: Marconi's team wins EFA DASS , January 29, 1992
  13. ↑ a b Flightglobal: Eurodass wins EFA EW contract , 25-31. March 1992 (PDF; 1.5 MB)
  14. ↑ Flightglobal: Spain to consider re-joining DASS , February 24, 1993 (PDF; 1.5 MB)
  15. ↑ a b c d e Troop service - radar and self-protection
  16. ↑ Flightglobal: DASA develops a towed radar decoy for Transall , May 8, 1996
  17. ↑ Flightglobal: Germany buys off-the-shelf DASS , 22 May 1996
  18. ↑ Flightglobal: DASA and GEC aim to settle DASS dilemma , 5-11. June 1996 (PDF; 336 kB)
  19. ↑ Flightglobal: ... as GEC test-flies new towed-decoy , 24 Jul 1996
  20. ^ Flightglobal: Raising the tempo , April 16, 1997
  21. ↑ Flightglobal: Germany thinks again on EF2000 defense system , 3-9. September 1997
  22. ↑ Flightglobal: Eurofighter carries out first supersonic tests with decoy , 25 Feb 1998
  23. ↑ Flightglobal: Dasa continues to test decoy despite ministry doubters , April 29, 1998
  24. ^ Flightglobal: Shared experience , June 16, 1999
  25. ↑ flightglobal: RAF aims for multiple arrays , 1996
  26. ↑ Flightglobal: Eurofighter weapons, radar and sensor updates mooted , Jun 13, 2000
  27. ↑ Flightglobal: Eurofighter Aids contract awarded , 22 Jun 2001
  28. ↑ Bernard C. Nalty: TACTICS AND TECHNIQUES of ELECTRONIC WARFARE - Electronic Countermeasures in the Air War Against North Vietnam 1965–1973 , August 17, 1977 (PDF; 12.3 MB)
  29. ↑ Avionics Today: New Sensors are Force Multipliers , May 1, 2007
  30. ↑ Sweetman: FIGHTER EW. THE NEXT GENERATION , Journal of Electronic Defense, July 2000
  31. ↑ Flightglobal: Preparing for production , Feb 25, 1998
  32. ↑ a b c d e f g h airpower.at: DASS / Defensive Aids Sub System , accessed on August 26, 2013
  33. ↑ Eurofighter Typhoon - Staying Ahead ( Memento of the original from September 15, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 215 kB) @1@ 2Template: Webachiv / IABot / defense.ge-ip.com
  34. ↑ a b c d e f starstreak - defenses ( Memento of the original from May 17, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / typhoon.starstreak.net
  35. ↑ Wired: The new Eurofighter is ready for electromagnetic combat , April 16, 2012
  36. ↑ a b c d Patent US 6822583 B2 from BAE Systems: Method for passive “360-degree coverage” tactical fighter target tracking incorporating adaptive pilot maneuver cue processing , 2002
  37. ^ Bill Sweetman: Eye of the storm: Eurofighter Typhoon's EW suite is central to the aircraft's power , Journal of Electronic Defense, July 1, 2002
  38. ↑ a b c d Fiszer, Michal: Typhoon Arises , Journal of Electronic Defense; Sep 2005, Vol. 28 Issue 9, p46
  39. ↑ a b ELETTRONICA - Technical Solutions ( Memento of the original dated November 2, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.elt-roma.com
  40. ↑ EFProfil 2009 - p. 8/12 "LO aircraft: target acquisition by radar / EF: target acquisition by radar warning receiver and / or radar" ( Memento from November 5, 2012 in the Internet Archive ) (PDF; 2.4 MB)
  41. ↑ Flightglobal: Europeans seek out radar killer , 28 Aug 2001
  42. ↑ Patent WO 2006135416 A2 from BAE Systems: Passive, rf, single fighter aircraft multifunction aperture sensor, air to air geolocation , 2005
  43. ↑ a b c d e Elettronica SpA - New technologies and innovative techniques for new-generation ECM systems ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 1.4 MB) @1@ 2Template: Webachiv / IABot / www.myaoc.org
  44. ↑ a b V. Alleva, G. Pinto / Elettronica: Modern radar and EW systems call for the large scale use of GaAs MIC and MMIC , Gallium Arsenide Applications Symposium 1994, April 28-30, 1994, Turin, Italy (PDF; 1, 4 MB)
  45. ↑ deagel: EuroDASS / Praetorian
  46. ↑ a b c Revista de Aeronáutica y Astronáutica: EF2000 LA RESPUESTA (Especial Eurofighter) , nº 769, December 2007 (PDF; 10.9 MB)
  47. ↑ a b c d e Flightglobal: Typhoon sectional view , accessed on August 26, 2013
  48. ↑ a b Chris Worning / EADS: Operational Capabilities of The Eurofighter Typhoon (PDF; 12.6 MB), accessed on April 15, 2013
  49. ↑ aviationweek: A Stealthier Rafale? , April 5, 2010 ( Memento of the original from October 18, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.aviationweek.com
  50. ^ Association of Old Crows: AOC 44th Annual International Symposium and Convention , Wednesday, October 31, 2007 (p. 17/19; PDF; 284 kB)
  51. ↑ Eurofighter WORLD: Typhoon prepares for leap in capability , issue 2/2012 ( Memento of October 7, 2012 in the Internet Archive ) (p. 9/24)
  52. ↑ a b c Luca Peruzzi: Aircraft self-protection against sophistication , Armada International, December 1, 2013
  53. ↑ Selex Galileo Ariel Mk II (attached to the left pod in the picture)
  54. ^ Praetorian defensive aids system (International) - Jane's Radar And Electronic Warfare Systems
  55. ↑ Ted Hooton, MILTECH: The Maturity of Eurofighter , 7/2008  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Dead Link / de.scribd.com  
  56. ↑ Klass, PJ; Nordwall, BD: GEC-Plessey avionics expects to win contract for EFA defense system , Aviation Week & Space Technology; 10/21/1991, Vol. 135 Issue 16, p47
  57. ^ National Museum of American History's Chip Collection: GEC-MARCONI MATERIALS TECHNOLOGY LIMITED (PDF; 683 kB), accessed on August 26, 2013
  58. ↑ BAE Systems: Design and Performance of Microwave and Millimeter-wave High Efficiency Power Amplifiers , p27 / 44, 2005 (PDF; 2.9 MB)
  59. ↑ Eurofighter GmbH: Eurofighter Typhoon - Defensive Aids Sub System (DASS). In: Youtube. November 8, 2013, accessed November 11, 2013 .
  60. ↑ BAE Systems - New Helmet Enables Typhoon Pilots to Look, Lock-on and Fire!
  61. ^ Diehl Defense - IRIS-T European Short Range Air-to-Air Missile
  62. ↑ PANORAMA DIFESA: Typhoon continua a crescere , GIUGNO 2013
  63. ^ IHS: NATO STANAG 4579: ED 1 , accessed August 26, 2013
  64. ↑ Raytheon: Battlefield Target Identification Device (BTID) ( Memento of the original from September 4, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed August 26, 2013 @1@ 2Template: Webachiv / IABot / www.raytheon.com
  65. ↑ Aerospace Insight Blog: Typhoon - the best is yet to come , March 8, 2013 ( Memento of the original from October 23, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / media.aerosociety.com
  66. ↑ ausairpower: The Russian Philosophy of Beyond Visual Range Air Combat , 2008
  67. ↑ Jane's Air-Launched Weapons 2002
  68. ↑ a b c d e Bodenseewerk Geräteechnik GmbH (BGT): ADVANCED TECHNOLOGY DEMONSTRATOR FOR IR IMAGING MISSILE WARNING SYSTEM , February 19, 2002
  69. ↑ a b c Ingo Schwaetzer: Multiple use of an IR missile approach warning system. Proc. SPIE 5074, Infrared Technology and Applications XXIX, October 10, 2003
  70. ↑ Saab Group: BOL Countermeasures Dispenser with superior endurance  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 243 kB), accessed on August 27, 2013@1@ 2Template: Dead Link / www.saabgroup.com  
  71. ^ O. Holt: Technology Survey - Airborne Dispensers and IR Expendables , The Journal of Electronic Defense, Vol. 34 No. 6th
  72. ↑ Chemring: CHAFF PACK BOL CCM 184 , accessed on August 27, 2013
  73. ↑ Alloy Surfaces: MJU-52 / B BOL IR Pre-emptive decoy ( Memento of the original from January 14, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (pdf), accessed on August 27, 2013 @1@ 2Template: Webachiv / IABot / www.alloysurfaces.com
  74. ↑ Chobham: Military Aircraft Countermeasures , accessed August 27, 2013
  75. ↑ Chemring: Countermeasures (PDF; 1 MB), accessed on August 27, 2013
  76. ↑ Chemring: Product data sheet Issue 1 - Typhoon IR Decoy No1 Mk1 Cartridge Countermeasure
  77. ↑ Goran Sven Erik Pettersson: An Illustrated Overview of ESM and ECM Systems , NAVAL POSTGRADUATE SCHOOL MONTEREY, September 1993